Relays and Contactors - How Do They Work and What is the Difference

[@PremKumar-mf6ud]

finally i found some video without graphical explanation and with a practical example.

[@TimWilborne]

Glad it was helpful!

[@trevonwalker8022]

Exactly. No one needs all that graphical information we just need to see it for what it is in the physical world lol then we'll be able to understand it graphical

[@csandoval82]

Great video. I’m a lineman trying to wire a control circuit for a three phase converter. Lol. I’m kind of out of my field a little but your videos are helping me along. Keep it up. 👍

[@TimWilborne]

Good to hear!

[@nigelnovak3096]

Hey Tim that was really clear, concise. Fantastic video. Big thanks!

[@TimWilborne]

Glad you enjoyed it! Thank you for your kind words Nigel.

[@elias2024]

Very helpful video, thank you!

[@TimWilborne]

You are welcome

[@rejeevesundar3982]

That's a really great video. Truly serving the purpose i came for. Thanks

[@TimWilborne]

Glad to hear it!

[@KW-ei3pi]

Tim, why is the voltage rating so different between AC and DC? (In the video at 0:50-1:25) I have a relay I was going to use for a 90v DC motor rated 5 amps. My relay is rated 28v DC at 10amps. Will that work? What is the important rating, volts or amps, or both? Should I use a contactor instead? Thanks very much! Regards

[@TimWilborne]

Probably not. Clint does a good job of explaining why in this video. kzbin.info/www/bejne/maW8faCwnaeIlbs

[@KW-ei3pi]

@@TimWilborne Thanks Tim, but I still don't understand the vast difference in AC and DC ratings. The relay I mentioned above is rated 250VAC ~/ 28VDC 10A. Why such a difference? Volts are volts, right? Thanks

[@TimWilborne]

@@KW-ei3pi No, volts are not volts...there lies the problem. AC is a SINE wave which mean it crosses 0V 60 times a second (60Hz) or roughly every 16 to 17 milliseconds. DC is constant. When you try to open a relay contact, you will produce an arc. AC sees that arc for a maximum of 16 to 17 ms. DC will see that arc until the relay contact moves far enough away to break the arc. That is why is is common to see AC voltage ratings 10 times higher than DC ratings and even then the amperage rating may not be the same. If I have to switch a DC load in one of my panels, I usually will select a solid state relay. Here is another video Clint did that may help with those. kzbin.info/www/bejne/hKGpdoRspqtkgKc

[@KW-ei3pi]

@@TimWilborne Awesome. Thanks! I will probably see if I can find a Contactor that will work. But shopping for one has so far been difficult. Thanks again.

[@KW-ei3pi]

@@TimWilborne One more question, Tim. The circuit has a Potentiometer. It's normally set to a very low speed before the DC motor is started. It's connected to the S1, S2, and S3 terminals of the Motor Controller. Does that limit the voltage to the motor and thus reduce the risk of damage to the contacts of the relay or contactor? Thanks

[@kendallsmith2036]

Thanks for the clear explanation and examples really helped me!

[@TimWilborne]

Great to hear Kendall!

[@dwaynes5983]

TW Controls has the best knowledge I seen in years. I never took his course because too far away from long island but do recommend it.

[@kennethquist6906]

Great video sir!♥️

[@TimWilborne]

Glad you liked it Kenneth!

[@edmondhodaj5817]

In a scenario in a multiple storey building if you have: multiple occupancy, communal gas boiler that does heating, Communal chiller that does chilling, Heating and cooling controlled in form of dps switches, static ps, and temp sensors, Pumps to regulate the flow operate on a duty/ assist/ standby, A sample video of how safety circuit can be manually isolated and reinstated from the panel, ( relays are 24v DC)

[@TimWilborne]

Hi Edmond. We have some safety videos coming that will hit the basics of this. Thanks for watching!

[@jeffreybrandt786]

add "Economizing Coil(s)", for DC coil- type contactors, just for additional clarity. Good basic video , for sure.

[@BlackAdam2784]

Great vid !

[@TimWilborne]

Thank you!

[@luisvaz92]

What would stop me from using a relay instead of a contactor aside from the amperage or voltage? If the relay has pretty much the specs that I need for my aplication, thanks. Great video.

[@TimWilborne]

Typically you just need to make sure it states that it has a horsepower rating higher than your motor. Many "relays" have low horsepower ratings despite having a high amperage rating.

[@luisvaz92]

@@TimWilborne Thanks, Tim. I learned how to wire a PLC thanks to you by the way. Regards.

[@corneliobraun4659]

Can you make a video on how to make a 230v 3phase box? Like what parts I would need!?

[@TimWilborne]

Do you mean something such as this kzbin.info/www/bejne/a6GWc513YrBjipY

[@mohamedsaeed932]

Superb. Thank you so much.

[@TimWilborne]

You are welcome. Thank you for your kind comments.

[@sandeepmasal7614]

Sir, Please make video on selection of contactor according to hp of motor ,what are the favor taking for consideration while selecting switch gear like mcb,mpcb, contactor

[@sandeepmasal7614]

Factors

[@TimWilborne]

I can do that. I'll put it on the list. Thank you for the suggestion Sandeep!

[@josephogello9317]

@@TimWilborne where can we connect neutral on 3 pole magnetic forward and reverse contactor

[@alexprowse5120]

Do you have any hvac wiring trainer boards?

[@TimWilborne]

Hi Alex, what would you envision it having?

[@etimemmanuel5884]

Great Job

[@TimWilborne]

Thank you!

[@user-yh4kl3hx2o]

Amazing bro

[@TimWilborne]

Thanks 🔥

[@GaryBrown-uz4in]

Hi Tim, I just discovered your channel today and I'm enjoying (and learning) watching the series. My control panels are for my DIY CNC machines, so happily the voltages and amperages are smaller, but the same concepts often apply. However, I have a question: I inadvertently bought a contactor with a 24VAC coil, when I have 24VDC in my panel. The coil activates with 24VDC and coils, as you point out, are simple electromagnets. Do you know how a 24VAC coil would be different from a 24VDC coil? Thanks Gary

[@TimWilborne]

Hi Gary. In some cases, 24V coils can be used with AC and DC but for the most part 24VDC coils are larger. My advice is if doesn't say 24VDC, swap it out.

[@darnellwalker880]

Tim, do I have to be a certified electrician to work with motor controls?

[@TimWilborne]

No you just need some basic troubleshooting tools but becoming a certified electrician is a great goal to shoot for.

[@dwaynes5983]

Not at all. I been doing for over 30 yrs including building electrical troubleshooting. Getting qualified as a controls technician is a great addition. I'm working on it now. Next year I'm becoming a full contractor. Lots of east coast travel.

[@hetanhawke1695]

thanks Mr

[@TimWilborne]

You are welcome Hetan

[@dharmikchauhan5608]

Nice

[@TimWilborne]

Thanks

[@mike4637]

3phase 240v????

[@TimWilborne]

Yes it exist. Was that your question Mike?

[@ortujexinol]

😂ill give my parts guy the exact part number and sometimes he will order something close to the exact numbers and surprisingly say," what? It's close enough!" Im like, " No! Jeez, there is a reason why the p/n numbers aren't the same!" I blame the maintenance manager for hiring him.😅

[@TimWilborne]

Yes, one letter can make a major difference!

[@OBJECTSHOWNERD]

1k

[@TimWilborne]

😁